GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

sealing old walls from the inside

andykahn | Posted in Energy Efficiency and Durability on

We are remodeling a recently purchased 1883 farmhouse. We have a few of the exterior walls open on the inside which I would like to air seal and waterproof while it is open. It was built with Douglas fir shiplap siding directly on the studs. The previous owner had insulation blown in about five years ago. Both siding and framing seem to be in good shape, but you can see light at some of the siding laps. I thought of rolling Prosoco R-guard on the back with tape or fabric on the joints but their technical advisors did not recommend that idea.

I feel like the house has lasted this long because there was so much air movement through the walls that any water could dry out. That protection probably goes away with insulation in the walls. Any ideas that would improve air and water sealing from the inside without causing more serious problems?


GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. brian_wiley | | #1

    Hi Andy, this article on Fine Homebuilding might be of help:

    I think the big take-away is that you’ll want some sort of gap between the inside of siding and your insulation to maintain that drying potential.

  2. andykahn | | #2

    Thanks for that link Brian. That may be my best solution.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |